Using third equation of motion:
Vf^2 - Vo^2 = 2as
Where,
Vf = 0
Vo = 48 mi/hour
= 0.4 ft/sec.
a = acceleration
s = distance
Substituting values:
0 - 70.4^2 = 2as
s = -70.4^2/2s
s = - 2478.08/a -------(1)
Using Newton's 2nd Law of Motion
F = ma
F = coefficient of friction x Normal force
Normal force = mg
F = 0.103(mg)
where
m = mass
g = acceleration due to gravity
= 32.2 ftm/sec^2
Substituting values,
0.103(m)(32.2) = ma
Simplifying:
0.103(32.2) = a
a = 3.32 ft/sec^2
Now,
Substituting the values in equation (1)
we get,
s = 2478.08/3.32
s = 747.18 feet
